Thermostability

Within these organisms are macromolecules (proteins and nucleic acids) which form the three-dimensional structures essential to their enzymatic activity.

[2] Above the native temperature of the organism, thermal energy may cause the unfolding and denaturation, as the heat can disrupt the intramolecular bonds in the tertiary and quaternary structure.

An example of such is the denaturing of proteins in albumen from a clear, nearly colourless liquid to an opaque white, insoluble gel.

One notable difference is the presence of extra hydrogen bonds in the thermophile's proteins—meaning that the protein structure is more resistant to unfolding.

The feed is typically treated with high pressure steam to kill bacteria such as Salmonella.

[12] The increase in temperature causes the E. coli proteins to precipitate, while the P. abyssi alkaline phosphatase remains stably in solution.

These enzymes are responsible of the degradation of the major fraction of biomass, the polysaccharides present in starch and lignocellulose.

All of these processes often involve thermal treatments to facilitate the polysaccharide hydrolysis, hence give thermostable variants of glycoside hydrolases an important role in this context.

A number of site-directed and random mutagenesis techniques,[14][15] in addition to directed evolution,[16] have been used to increase the thermostability of target proteins.

Comparative methods have been used to increase the stability of mesophilic proteins based on comparison to thermophilic homologs.

[27][28] Certain poisonous fungi contain thermostable toxins, such as amatoxin found in the death cap and autumn skullcap mushrooms and patulin from molds.